package demoSingleton;

public class School {
    public static void main(String[] args) {
        Principal principal = Principal.getInstance();
        principal.ammounceMent("全校周五放假");
        principal.approveFile("通过全校周五放假的文件");

        Principal principal1 = Principal.getInstance();
        System.out.println("是否同一个校长? " + (principal1 == principal));
    }
}
